P1 - Energy calculations Flashcards
P1 - How do you calculate an object’s weight?
weight = mass × gravitational field strength
P1 - How do you calculate work done?
work done = force × distance
P1 - What is the equation that links force, extension and spring constant?
force applied = spring constant × extension
P1 - How do you calculate the speed of an object?
Speed = Distance / Time
P1 - How do you calculate the kinetic energy of an object?
kinetic energy = 0.5 × mass × (speed)2
P1 - How do you calculate an object’s GPE?
Gravitational potential energy = mass × gravitational field strength (g) ×height
P1 - How do you calculate the power generated by an object?
Power = Energy transferred / Time
P1 - What is the equation that links power, work and time?
Power = Work Done / Time
P1 - How do you calculate the energy transferred by an object?
Energy transferred = power × time
P1 - How do you calculate the efficiency of an appliance?
Efficiency = Useful out / Total in
P1 - what energy transfers take place when a student does a bungee jump.
Before the jump:
- A store of GPE because the student is up high.
During the jump:
- GPE store goes down and the kinetic store increases because the student is moving.
After the jump:
- When the bungee cord is stretched it stores elastic potential energy.
P1 - what energy transfers take place when a student Lifts a weight from the floor to above his head.
Before the lift:
Student has a store of chemical energy in his muscles.
During the lift:
Chemical energy is converted to kinetic energy as the student moves the bar
After the lift:
Kinetic energy is converted to GPE because the bar is stationary above the students head.
P1 - what energy transfers take place when a battery is used to light up a bulb in an electric circuit.
Before turning the circuit on:
The battery stores chemical energy
After turning the circuit on:
Chemical energy is converted to electrical energy.
When the bulb is lit:
Electrical energy is converted to light and heat.
